Digester



(No Model.)

' B; F, RADPORD.

DIGBSTER.

No. 483,942. Patented Oct. 4, 1892.

INVENTUR I `l Il lll-.

| l l l l l l l- WITNEEEEE 'me News Pneus no., muvo-Limo., wAsmNn yUNrrED STATES PATENT GEEICE.

BENJAMIN E. RADEoRD, or HYDE PARK, MASSACHUSETTS.

DIGESTER.

SPECIFICATION forming part of Letters Patent No. 483,942, dated October4, 1892.

Application tiled June 15, 1891. Serial No. 396,375. (No model.

To @ZZ whom t may concern:

Be it known that I, BENJAMIN F. RADEORD, acitizen of the United Statesof America, and a resident of the town of Hyde Park, in the county ofNorfolk and State of Massachusetts, have invented certain new and usefulImprovements in Digesters, of which the following is a full, clear, andexact description.

This invention relates to digesters to be used more especially in themanufacture of sulphite-pulp, and particularly to the domes of thedigesters, which heretofore in some instances, and preferably, have beenmade of solid bronze metal.

'The object of this invention is to produce these domes in each andevery respect practically equal to the domes of solid bronze metal andin a manner requiring comparatively but a small quantity of bronzemetal, thereby materially reducing their cost of manufacture.

The dome of this invention, in substance, is constructed of thecombination of two separate layers of metal-to wir, an outer layer ofiron or other such like metal and an inner layer of bronze or other suchlike metal. The outer iron layer, preferably in one piece, as usual, hasupwardly-extending man and inlet holes, each provided with an outwardhorizont-al flange, and at its rim it sets upon an outward horizontalflange at one end of the digester-body. The inner bronze layer,preferably in one piece, is shaped to closelylie against and line thewhole inner surface of the iron outer layer, including its said rim andthe in- 11er surfaces of the side walls of its man and inlet holes,vandat the outer end of each of said holes preferably it has a horizontalinwardlyprojecting iiange. An inner bronze layer and an outer ironlayer, shaped and iitted together as has been stated, constitute thedome of this invention, and it is secured to the digesterbody by meansof screw-bolts and screw-nuts, as Well known. Again, under thisinvention, in substance, the inner bronze layer at its portions liningthe man and inlet holes is held in position against the walls of saidholes by means of the covers of said holes and screwbolts and screw-nutsor such like applied to said covers and to said outward ianges of saidholes, in combination with a ring of metal, preferably of bronze, foreach of said holes,

and which lies between the cover and the outward iange of the hole andalso upon said inward iiange of the inner bronze layer, and means-suchas headed screw-bolts and screwnuts-applied to said iianges of the innerbronze layer and said rings.

In the drawings forming part of this speciiication, Figure l is a planView of the digester-dome of this invention. Fig. 2 is a centralvertical section on line 2 2, Fig. 1.

In the drawings,A is the iron or outerlayer and Bis the bronze or innerlayer of the dome, and each layer preferably is in one piece. The ironouter layer A is shaped as usual and has an upwardly-projecting manholeA2, inlet-holes A3 A4 A5 A6, respectively, and a rim A7, which issuitable to set upon the upper face of an outward horizontal iiange C2,surrounding the open end of the digester-body C, and to which end thedome is to be attached by any suitable means-as, for instance, as wellknown, by headed screw-bolts D and screw-nuts E. Again, each man andinlet hole of the iron outer layer of the dome at its outer end issurrounded by a horizontallyprojecting flange F, and to these iiangesthe respective covers Gfor the man and inlet holes are attached, each bysuitable means, and all as well knoWn--as, for instance, by headedscrew-bolts and screw-nuts.

The bronze inner layer B is shaped to closely` lie against and therebyto line the whole inner surface of the iron outer layer A, including itsrim A7 and also the vertical inner wall A8 of its manhole A2 and thevertical inner wall A9 of each of its inlet-holes. Furthermore, withinsaid holes and at their outer end the bronzeinner layerB of each has ahorizontal inward-projecting liange B2, each covered by arin g J ofmetal, preferably bronze, and of suitable width otherwise to cover theoutward iange F of each of said holes, all so that by the attachment ofthe covers of said holes, as has been described, said rings are securedon the dolne, it being understood that previous thereto they weresecured to said flanges of the bronze inner layer of the dome by means,such as headed screw-bolts H and screw-nuts H2, properly applied to saidrings and said flanges, as shown.

From the above description it is plain that a digester-dome is producedhaving an iron IOO outer layer and a bronze innerlayer and in a mannerand combination such that the dome is in every substantial respectpractically equal to one made of solid bronze and the eX- pense of themanufacture of which is greatly reduced, for the reason that, ascompared with that of a dome of solid bronze, the amount of bronzenecessary is reduced to the minimum.

Although this invention has been particularly described as to be usedfor sulphite-pulp, it is not intended to limit it to that use, as it maybe used for other purposes Where bronze or other expensive metals arenecessary to resist the action of acids'. Y v

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is-

A dome or head for digesters, composed of seated on said ring and it andthe ring se.

cured to the iron flange, substantially as described, for the purposesspecified.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing f Witnesses.

, BENJ. F. RADFORD. Witnesses:

ALBERT W. BROWN,

MARION E. BROWN.

